Correct Option
The correct option isNorth-East Trade Winds
Explanation
The rainfall pattern in India is primarily dictated by the seasonal reversal of winds known as the monsoon. While the South-West Monsoon covers most of the country in summer, the winter rainfall along the southeastern coast is driven by the re-establishment of the planetary trade winds following the southward shift of the Inter-Tropical Convergence Zone (ITCZ).
Option Analysis
- South-West Monsoon is Incorrect: The South-West Monsoon (June to September) brings rainfall to the majority of the Indian subcontinent. However, the Tamil Nadu coast remains relatively dry during this season because it lies in the rain-shadow area of the Western Ghats and is situated parallel to the Bay of Bengal branch of the monsoon winds.
- North-East Trade Winds is Correct: During winter (October to December), the retreat of the monsoon leads to the establishment of high pressure over the Indian landmass. Winds blow from the land towards the sea in a North-East to South-West direction. These are the North-East Trade Winds (manifesting as the North-East Monsoon). As these winds traverse the Bay of Bengal, they pick up moisture and cause significant rainfall when they hit the Coromandel Coast of Tamil Nadu.
- Western Disturbances is Incorrect: Western Disturbances are extra-tropical storms originating in the Mediterranean region. They are responsible for winter precipitation in North and North-West India (e.g., Punjab, Haryana, and the Himalayas), not the southern peninsula.
- Loo is Incorrect: Loo is a strong, hot, and dry wind that blows during the summer afternoons over the plains of North and North-West India. It is not a precipitation-bearing wind.
Key Takeaway: The Tamil Nadu coast receives the bulk of its annual rainfall during the winter season from the North-East Monsoon, which consists of moisture-laden North-East Trade Winds blowing from the Bay of Bengal.